1. Field of the Invention
The present invention is directed to improvements in a mechanical seed meter having an internally mounted seed knockout assembly.
2. Description of the Prior Art
In the United States the vast majority of crops are planted with row crop planters, grain drills or air seeders. Row crop planters are designed to place seeds in rows far enough apart to permit the control of weeds by cultivation and to improve harvesting efficiency. Grain drills and air seeders are used in solid planting, when row spacing is too close to permit cultivating or other cultural practices.
All three seeding machines, meter seed so it can be planted uniformly in a field. The row crop planters usually have the more sophisticated metering equipment for singling seeds, whereas the drills and air seeders use volumetric meters which apply a fixed volume of seed per linear foot.
Mechanical seed meters used on row crop planters include seed plate meters, finger pickup meters and xe2x80x9cbrush metersxe2x80x9d. In a xe2x80x9cbrush meterxe2x80x9d, a rotating circular member having a plurality of seed receiving cells passes through a seed puddle. Seed is trapped in the seed receiving cells by brushes. Brush meters may also be provided with external seed knockout assemblies for freeing trapped seeds from the seed cells, see U.S. Pat. No. 5,784,985. These external seed knockout assemblies are currently used on xe2x80x9cbrush metersxe2x80x9d marketed by the assignee of the present patent application. However, the knockout wheels used on the production versions are sprocket wheels having outwardly extending radial teeth that enter the seed receiving cells to release trapped seed. With these externally mounted seed knockout assemblies, the trapped seed is returned to the seed puddle. As such, the seed meter has skipped a planting location because of the jammed seed receiving cell. In addition, the previously trapped seed may again enter the same or another seed receiving cell and become trapped again because of that seed""s unique geometry.
It is an object of the present invention to provide a simple and effective internally mounted seed knockout assembly for a seed meter.
It is a feature of the present invention that the internal knockout assembly is an integral part of the brush retainer ring of a brush meter.
A brush meter is provided with a stationary housing having an inlet for receiving seed from a seed hopper and an outlet through which metered seed is dispensed into a seed tube. A brush retainer ring is mounted to the stationary housing. The brush retainer ring is provided with a radially extending brush that together with the stationary housing defines a seed trapping zone. A bowl having a plurality of seed receiving cells located about its periphery is rotatively mounted to the housing. The seed receiving cells cooperate with the seed trapping zone to trap single seeds. The individual seeds are released from the seed cells at the outlet. An internally mounted seed knockout assembly positively ejects trapped or jammed seeds from the seed receiving cells. The seed knockout assembly comprises a rotatable sprocket wheel having radially raised teeth that enter the individual seed cells of the bowl driving the trapped seed into the outlet. Therefore a seeding location is not skipped by a trapped seed.
The internal seed knockout assembly is an integral part of the brush retainer ring. The brush retainer ring shields the knockout sprocket from the seed in the seed puddle. In addition, the brush retainer ring is provided with a shaft on which the sprocket wheel rotates.